Prevalence of multimorbidity in Brazilian individuals: A population-based study

This study aimed to estimate the prevalence of multimorbidity in Brazilian individuals and its association with sociodemographic and lifestyle factors. This cross-sectional study used data from the National Health Survey conducted in 2019 with 88,531 Brazilian adults Multimorbidity is the presence of two or more non-communicable chronic diseases. Associated factors were assessed by calculating the prevalence ratio (PR) obtained using Poisson regression with robust variance. Multimorbidity was estimated in 29.9% (95%CI: 29.33% to 30.48%) of Brazilian individuals. In the multiple models, the prevalence was high in women (PR: 1.37; 95%CI: 1.32 to 1.42), individuals over 60 years (PR: 4.26; 95%CI: 3.87 to 4.69), non-employed (PR: 1.20; 95%CI: 1.15 to 1.26), individuals with obesity (PR: 1.49; 95%CI: 1.43 to 1.56), and smokers (PR: 1.24; 95%CI: 1.19 to 1.29). This study identified a high prevalence of multimorbidity and its association with sociodemographic and lifestyle factors. The monitoring of these outcomes may support the development of policies and services.


Unfunded studies
Enter: The author(s) received no specific funding for this work.
The increasing prevalence of NCDs is a worldwide phenomenon resulting from the westernization of lifestyle processes and population aging.Obesity, unhealthy eating habits, physical inactivity, and smoking are etiological factors contributing to NCDs (e.g., diabetes, high blood pressure, and cancer) [1, 6 -9].Data from the 2013 National Health Survey (NHS) involving 60,202 individuals showed that 23.6% of the population has multimorbidity, which was mainly associated with sex (women), aging, low education level, smoking, and obesity [1].
The prevalence of multimorbidity in Brazilian adults directly impacts their quality of life and public health costs.In this sense, its monitoring is needed to create integral public policies focused on social and lifestyle factors [1,6].
Therefore, this study aimed to estimate the prevalence of multimorbidity in Brazilian adults over 18 years in 2019 and its association with sociodemographic and lifestyle factors.

Methodology
This cross-sectional study analyzed data from the National Health Survey 2019 A total of 108,525 households were visited across the country, and 94,114 interviews were performed.The non-response rate was 6.4% [10].
We analyzed 88,531 responses about the lifestyle of Brazilian individuals.
Multimorbidity was defined by the presence of two or more NCDs.In this study, the condition was self-reported and based on the response to the question "Has a doctor ever diagnosed you with (name of the condition)?".The following NCD were considered: systemic arterial hypertension, diabetes, hypercholesterolemia, heart problems (infarction, angina, or heart failure), stroke, asthma or bronchitis, arthritis, chronic back pain, work-related musculoskeletal disorders, depression, mental illness, lung diseases, cancer, and chronic kidney disease [10].
The association measures were organized according to sex, age group, ethnic group (self-reported), education level (years of schooling), occupation, physical activity, body mass index (BMI), alcohol consumption, smoking, residence area (urban or rural), Brazilian macro-regions (north, northeast, southeast, south, and midwest), private health insurance, and medical care in the last year [10].
Alcohol consumption was classified as abstaining, moderate (two drinks a day for men and one drink a day for women), or excessive (five drinks or more in a day for men and four drinks or more in a day for women).Smoking was classified as never smoked, ex-smoker, or smoker [11].For BMI, we used the World Health Organization (WHO) classification: underweight (BMI < 18.5 kg/m 2 ), normal weight (BMI between 18.5 and 24.5 kg/m 2 ), overweight (BMI between 25 and 29.9 kg/m 2 ), and obesity (BMI ≥ 30 kg/m 2 ).Physical activity was classified as none, not enough, or enough, according to the total number of minutes per week dedicated to physical exercise, sports, leisure, efforts at work, commuting from work, or other displacements and household chores that involved physical effort.The WHO classifies the level of physical activity as moderate (75 to 150 minutes) or intense (150 to 300 minutes) [12].
Poisson regression with robust variance verified associations between multimorbidity and independent variables; data regarding the prevalence ratio (PR) of multimorbidity and 95% confidence intervals were also estimated.

Results
The   Regarding lifestyle factors, smokers (40.46%; 95%CI: 39.30 to 41.63) and individuals with obesity (40.85%; 95%CI: 39.56 to 42.15) had the highest estimated values for multimorbidity.The prevalence of multimorbidity according to independent variables is described in Table 2.All variables were included in the multiple regression model.The multiple regression showed that the prevalence of multimorbidity among women (PR: 1.37; 95%CI: 1.32 to 1.42) was 37% higher than in men, regardless of other variables.In the adjusted analysis, the prevalence significantly increased with age: multimorbidity was 3.26-fold higher in individuals over 60 years (PR: 4.26; 95%CI: 3.87 to 4.69) than in individuals aged between 18 and 29 years.
Individuals with obesity (PR: 1.49; 95%CI: 1.43 to 1.56) and who smoked (PR: 1.16; 95%CI: 1.09 to 1.23) also had a higher prevalence of multimorbidity than individuals with normal weight and those who never smoked, respectively.
The southeast region (PR: 1.23; 95%CI: 1.16 to 1.32) presented the highest prevalence of multimorbidity compared with the other Brazilian regions.
Systemic arterial hypertension, chronic back pain, and hypercholesterolemia were the most prevalent NCDs in both sexes, as observed in NHS 2013 [1].This result emphasizes the need for attention, especially within the scope of public health.
Regarding associations between sociodemographic factors and multimorbidity, a study conducted with 5,074,227 individuals in the Netherlands observed that unemployed individuals were more likely to have at least three than those employed [1].These findings corroborated our results since non-employed individuals had a higher prevalence of multimorbidity, regardless of age, sex, or education level.
Individuals with private health insurance had a higher prevalence of multimorbidity than those with no private health insurance.Moreover, individuals who had at least one medical appointment in the year before the survey showed a 2.59-fold increase in the prevalence of multimorbidity compared with those who did not seek a doctor.Access to health services and the accurate diagnosis of NCDs may be easier in private than in public health, favoring prevention.These results may be justified by the question asked during the survey ("Has a doctor ever diagnosed you with (name of the condition)?"), which probably influenced the number of cases of multimorbidity among individuals who had easy access to medical care.
The north region of Brazil, which is the least economically developed, had the lowest prevalence of multimorbidity compared with other regions.In contrast, the southeast and south regions (most economically developed regions) had the highest prevalence of multimorbidity.In addition, the north region of Brazil has specific geographic characteristics (i.e., many rivers, dense vegetation, and a wide territory with low population density) that may justify the difficult access to health services [1,2].A survey conducted by the Institute of Studies for Health Policies [1] showed that many older individuals from the north region never performed a blood test to measure cholesterol or blood glucose compared with other regions of Brazil.The literature and our results suggested low access to diagnosis and screening of NCDs in the northern region of Brazil.
Lifestyle factors were significantly associated with multimorbidity.We found a high prevalence of multimorbidity in individuals with obesity (49%) and smokers (24%) compared with those with normal weight and who never smoked, respectively.Similarly, a 20-year cohort study conducted in the United Kingdom with 4,510 individuals aged between 15 and 55 years found an increasing prevalence of multimorbidity.Smoking and obesity were strong independent predictors of multimorbidity [3].
The association between multimorbidity and lifestyle should be a strategy for creating health policies to prevent and treat NCDs in adults and older individuals.These variables may also be important for a comprehensive and multidisciplinary planning, including holistic health and social care, and would reduce the burden of multimorbidity and disadvantages related to lack of prevention, treatment, or follow-up of individuals.
The Brazilian public health system has public policies to treat and control NCDs, such as the Network of Non-Communicable Chronic Diseases, the National Program for Attention to Arterial Hypertension and Diabetes Mellitus, and many other programs created especially for women and older individuals.Based on this context and the correlation with other diseases, it is possible to treat or control NCDs using lifestyle and therapeutic interventions, justifying the public investment in these policies [1][2][3][4].
The present study had some limitations.The self-reported diagnosis of NCDs may have underestimated the prevalence of multimorbidity.The cross-sectional design may have also precluded the analysis of causal relationships.Nevertheless, the use of a population database and complex statistical analyses allowed us to extrapolate the results for the entire Brazilian population.

Conclusion
The prevalence of multimorbidity in Brazilian individuals has been increasing since the NHS 2013.Systemic arterial hypertension, chronic back problems, and hypercholesteremia were the most prevalent NCDs in both sexes.
The prevalence of multimorbidity was associated with sociodemographic and lifestyle factors.Therefore, these characteristics are essential to health services for planning strategies to prevent, treat, and control multimorbidity.
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NHS 2019) conducted by the Brazilian Ministry of Health and the Brazilian Institute of Geography and Statistics (IBGE).Data were public and had unrestricted access [10].The NHS 2019 had a complex sampling designed in multiple stages, and sample selection was based on the IBGE master sample.The NHS 2019 assessed sociodemographic and lifestyle factors of Brazilian families in three parts: (i) the household; (ii) all household residents, focusing on sociodemographic and health information; and (iii) the selected resident, investigating information such as lifestyle, NCDs, and violence.Anthropometric measurements were also performed (sub-sample).

Fig 1 .
Fig 1. Distribution of NCDs in individuals with multimorbidity according to sex.
All data files are available from the IBGE-Instituto Brasileiro de Geografia e Estatística database (https://www.ibge.gov.br/estatisticas/downloads-estatisticas.html)Powered by Editorial Manager® and ProduXion Manager® from Aries Systems Corporation and contact information or URL).This text is appropriate if the data are owned by a third party and authors do not have permission to share the data.
The data underlying the results presented in the study are available from (include the name of the third party • Powered by Editorial Manager® and ProduXion Manager® from Aries Systems Corporation The Wald test assessed the significance of the models with p-value <0.05.All analyzes were performed using the statistical package STATA (Stata Corp. Inc.TX, USA, version 14) and adjusted for complex sample design.

Table 1 . Estimated prevalence of multimorbidity according to sociodemographic 96 characteristics, social determinants, lifestyle factors, and use of health services. 97
).

Table 2 . Prevalence of multimorbidity in Brazilian individuals according to lifestyle 115 and social factors. 116
Prevalence ratio; b CI: confidence interval; c p: Wald test; d BMI: body mass index.